Bathymetry around isolated volcanic islands and atolls in the South Pacific Ocean

Abstract

The results of bathymetric surveys around six isolated basaltic islands and atolls in Cook Group and three in the Tokelau group are presented. In all cases radial profiles approximate very closely to the equation y = y_oe ^−cw where y is the elevation of the sea bedabove the mean level of the surrounding ocean floor (y_o), x is the distance from the outer reef edge, and c is a constant. Using one km as the unit of length, the value of c for individual islands varies from 0.09 to 0.11, the average being 0.10. The use of this average value for a surrounding ocean depth of 4,500 m gives a maximumerror in the water depth of only 165m, and a sea bed slope near the reef of 24°